Adapter device for stitching letters

ABSTRACT

An adapter device removably mounted on a sewing machine bed for stitching letters of a kind but different in size with the use of a pattern cam assembly including a pair of transmitters to transmit the oscillations of cam followers tracing said pattern cam assembly to levers for moving a stitch frame two dimentionally in variable amplitudes.

United States Patent Taketomi 1151 3,682,118 1451 Aug. 8, 1972 1541ADAPTER DEVICE FOR STlTCl-IING LETTERS 72 Inventor: Bunsaku Talretomi,56-141 Azalshikane, Oaza-lwasaki, Nisshinc110, Aichi-gun, Aichi-ken,Japan 221 Filed: July 8, 1970 211 App1.No.: 53,101

52 u.s.c1. ..'....-....112/102 511 1111.01 ..D05c 3/02 [58]FieldofSearch ..112/102, 103

[56] References Cited UNITED STATES PATENTS 1,575,285 3/1926 Sibbardetal..112/102 3,082,720 3/1963 Sanbe ..112/102 3,096,737 7/1963 Bono ..l 12/103 X 3,112,718 12/1963 Bond ..112/102 3,168,064 2/1965 Fresard et a1..112/102 3,516,373 6/ 1970 Maeda ..112/102 Primary Examiner-Alfred R.Guest Attorney-Linton & Linton [57] ABSTRACT An adapter device removablymounted on a sewing machine bed for stitching letters of a kind butdifferent in size with the use of a pattern cam assembly including apair of transmitters to transmit the oscillations of cam followerstracing said pattern cam assembly to levers for moving a stitch frametwo dimentionally in variable amplitudes.

5 Clains, 7 Drawing Figures mmm 8 m2 SHEET 1 [IF 3 INVENTOR Y Bl/IVSHKUTAKE TOM/ ATTORNEYS PATENTEUA B 8 I SHEET 2 BF 3 INVENTOR BUNSRKUTAKETOMI BY M /M ATTORNEYS PATENTEU 8 I972 3,682, 1 l8 sum 3 [IF 3 Fig.5

m'EmoR BUNSRKU TA KETOM/ BY M w/M ATTORNEYS ADAPTER DEVICE FOR STITCHINGLETTERS This invention relates generally to a sewing machine and moreparticularly to an improvement in an adapter device to be set to thesewing machine for stitching letters.

In the conventional adapter device of this type, a pair of leverstracing a pattern cam assembly actuate a stitch frame, on which amaterial to be stitched is fixed, on a sewing machine bed. However ithas been impossible to stitch many letters of one kind but of differentsizes using aspecified pattern cam assembly because levers for movingthe stitch frame touch the pattern cams directly and the amplitudes ofthe oscillatory movements of the levers are not adjustable.

An object of the present invention is to provide an improved adapterdevice in which a pair of intermediate transmitters are located betweenthe cam followers and the levers to move the stitch frame in order tovary amplitudes of oscillations of the cam followers whereby lettersdifferent in sizes or in the ratio of height and breadth can bedoublicated froma specified pattern cam assembly.

The above and other objects of the present invention will be apparentfrom the following detail descriptions with respect to preferredembodiments and claims taken along with accompanying drawings in which:

FIG. 1 is a plane view of an adapter device embodying the presentinvention set to a sewing machine bed with some parts broken away acover member being taken away,

FIG. 2 is a plane view showing another combination of a mechanism formoving the stitch frame and the intermediate transmitters,

FIG. 3 is a view showing various letters to be duplicated from aspecified pattern cam assembly,

FIG. 4 is a perspective view of a sewing machine to be equipped with theadapter device according to the present invention,

FIG. 5 is a plane view of another embodiment of the intermediatetransmitter,

FIG. 6 is a sectional view taken along the line 55 in FIG. 5 and FIG. 7is a perspective view showing the mechanism for displacing intermediatetransmitters.

Referring to the drawings, in which similar reference numerals identifycorresponding parts throughout several views, a sewing machine comprisesa bed 10 secured to a machine frame not shown, a standard 11 upstandingfrom said bed, a bracket arm 12 and a head '13 earring a needle 14reciprocable vertically. A looper drive shaft 15 is journaled under thebed 10 and is adapted to be oscillated azimuthally from a main shaft(not shown) in the bracket arm 12 through a crank 16 secured to one endof the looper drive shaft 15 and through a pitman l7 pivotally engagingthe crank 16 which pitrnan is reciprocated vertically in the standard 11in accordance with the rotation of the mainshaft. The feed speed i.e.the period of the oscillilation of the looper drive shaft 15 is adjustedby a feeder dial 18 provided on the standard 11. The upper portion of apinion 19 projects vertically through a hole 20 bored through the righthand portion of the bed 10. The pinion 19 and a ratchet wheel 21 aresecured to a common vertical shaft 22 which is held by a frictionalforce in a degree that it can be rotated when given an appropreatetorque. The ratchet wheel 21 is engaged by a piston rod 23 which ispivotally connected at its one end to a connector 24 secured to theintermediate portion of the looper drive shaft 15. Thus, the ratchetwheel 21 is rotated by the reciprocating piston rod 23 when the looperdrive shaft 15 is oscillated. Next in an adapter device 25 to be mountedon the bed 10, a base plate 26 is provided with a fitting 27 and anelongated hole 28 to pass a mounting screw 29 as means for positioningthe base plate 26 on the bed 10 and has a pinion hole 30 to loosely passthe pinion 19. A case member 31 is fixed on the base plate 26 so as tocover the pinion hole 30. A thin guide member 32 is secured on the baseplate 26 alongthe longitudinal direction of the case member 31 and theheight of the guide member 32 is made smaller than that of theprojecting portion of the pinion 19 when the adaper device is mounted onthe bed 10. A pattern cam assembly 33 comprises a slide plate 34 adaptedto be slidable between a side wall 31'of the case member and the thinguide member, a lateral pattern cam 36 35 secured on the slide plate 34,and a longitudinal pattern cam 36 secured on the lateral pattern cam 35and having at its one longitudinal side a rack 19 to be in gear with thepinion 19. Curved surfaces 35 and 36' of the pattern cam assembly 33 areformed according to the conventional art so that a pair of cam followersto be described below are given necessary oscillatory movements toduplicate letters of a predetermined kind and size. A pair of camfollowers 37 and 38 are pivotally mounted by a common pivot 39 on thebed and their extended free ends 37 and 38 contact with curved surfaced35' and 36' respectively through an opening (not shown) through the wall31. A lateral linear lever 40 and a longitudinal angle lever 41 with twoarms 41 and 41" are pivotally mounted on the plate 26 by a common screw42. A circular spring 42 is mounted between the arm 41 and the laterallever 40 in order to bias them in a manner that tend to move said armand lever apart from each other but their displacements are limited by aspiral spring 42" secured on the base plate 26. A drive link 43 ispivotally connected at its one end to the end portion of the laterallever 40 by a pin 40' and is secured at the other end to a stitch frame44 on which a material to be stitched is secured. A connecting link 45is pivotally connected to the arm 41" of the longitudinal lever 41 andto the drive link 43 by pins 46 and 46'. Thus it is understood that thestitch frame 44 is moved laterally on a needle plate 47 when the laterallever 40 is rotated around the screw 42 and longitudinal when theiongitudinal lever 41 is rotated to rotate the drive link 43 around thepin 40'. The longitudinal and lateral travels of the stitch frame 44 aremade proportional to those of the arm 41" at 46 and of the lever 40 at40" respectively. In a mechanism for varing the style of letters to bestitched, a dial disk 48, which is to be fixed on a cover member 52, ispositioned over the base plate 26 around a post 49 set up on the baseplate 26. Between the disk 48 and a base plate 26, two rotary levers 50and 51 of different length are carried by coaxial hollow cylindricalshafts 50 and 51 respectively which are held around the post 49 at anarbitrary angular position by frictional force, but are rotatable ifactuated by a hand. On the dial disk 48 a pair of pointers 50" and 51"are secured to shafts 50 and 51 respectively to indicate the angularpositions of the rotary lever 50 and 51 respectively. An intermediatetransmitter 53 is pivotally connected to the rotary lever 50 at its oneend and at the other end has a laterally extending contact piece 53'which contacts with the side surfaces of the cam follower 37 and thelateral lever 40. A similar intermediate transmitter 54 with a laterallyextending contact piece 54 is connected to the rotary lever 51 andengages the cam follower 38 and the arm 41'. The operation of the aboveconstruction is as follows. The adapter device is mounted on the bed andthe pinion 19 projects through the holes 20 and 30. The pattern camassembly 33 for stitching a letter N, for example, is

inseted between the wall 31 and the guide member 32 and the rack 19'comes in gear with the pinion l9. Pushing astarter handle 55 formedintegrally with the lever 40 towards the intermediate transmitters 53and 54 and starting the sewing machine, a sewing machine operator canstitch a letter N as shown by 57in FIG. 3 on the material 56 carried bythe stitch frame 44 with the needle 14 reciprocating transversely. Ifthe operater rotates both of the rotary levers 50 and 51 clockwise fromthe positions shown if FIG. 1, the contact pieces 53" and 54' slidetowards the pivot 39 along the side surfaces of the followers 37 and 38respectively. Thus, the oscillations of followers 37 and 38 aretransmitted in more attenuated amplitudes to the lateral andlongitudinal levers 40 and 41. With this situation of the transmitters,a letter proportionally reduced as shown by 58 is stitched. If only therotary lever 50 is rotated clockwise, only the transmitter 53 slidestowards the pivot 39 and only the amplitude of the oscillation of thelever 40 is reduced. In this case, a letter reduced in breadth as shownby 59 is stitched. If only the rotary lever 51 is rotated clockwise, aletter reduced in height as shown by 60 is duplicated. The oscillatingamplitudes of cumfollowere 37 and 38 can be amplified, too by thecounterclockwise rotation of the rotary levers 50 and 51.

The mechanism for moving the stitch frame 44 can be replaced by thatshown in FIG. 2. In this mechanism, a longitudinal rod 61 and a lateralrod 62 are slidably supported in fixed aperture members 63. To one endportion of these rods are secured contact members 61' and 62' in contactwith contact pieces of the transmitter 53 and 54 respectively. The otherend of the rod 61 is pivotally connected to an arm of an angle lever 64rotatably supported by a pin 65. A guide rod 66 is slidably inserted inaperture members 67'and has a bifurcated holder 68 secured at its oneend, which holder is usually biased by a compression coil spring 66' tocontact with the other end of the rod 62. The holder 68 holds a shaft 69at right angle to the rod 66. A circular stitch frame 70 with twoextensions 70 and 70" has the shaft 69 slidably inserted through holesformed in said extensions. The extention 70" engages the other arm ofthe angle lever 64 and is usually biased to rotate the lever 64clockwise by a coil spring 71. Thus the rods 61 and 62 reciprocate asthe transmitters 53 and 54 oscillate and move the stitch frame 70longitudinally and laterally. As a means to transmit the amplitude ofthe cam follower, another construction shown in FIGS. 5 and 6 ispossible. A cam follower 72 is provided with grooves 73 on both sides. Abifurcated transmitter 74 is slidably mounted on cam follower 72ffaiisilifitf ifiiiiiliiifor"aifiiofiifvfifii'ii?2133% rod 75 ispivotally connected to the transmitter 74 and a rotatable disk 76. Therotation of the disk 76 slides the transmitter 74 towards or away from apivot 77 thereby to attenuate or amplify the amplitude of theoscillation of the follower 72.

As is clear from foregoings it is possible according to the presentinvention to stitch letters of a kind but different in sizes using aspecified patterncum assembly. Thus letters of various styles such asbroad one or tall one are doublicated freely on a material to bestitched by changing positions of the intermediate transmitters 53 and54 Having presented the disclosure of the invention, what I claim is:

1. An adapter capable of being detachably mounted on a sewing machinehaving a machine bed and a looper drive shaft driven pinion on said bed,for stitching designs on a work piece comprising a base plate mountableon the sewing machine bed and having an opening for the looper driveshaft driven pinion to extend therethrough, a cam assembly having a rackfor meshing with said pinion and two cam patterns, a work supportingframe, a lever pivotally mounted on said base plate, a link connectingsaid lever to said work frame for imparting lateral movement thereto, asecond lever pivotally mounted on said base plate, a second linkconnecting said second lever to said first link for impartinglongitudinal movement to said work frame, cam followers levers pivotallymounted on said bed plate and each in contact with a different one ofsaid cam patterns, motion transmitting means pivotally supported on saidbase plate and interposed between said cam followers levers and saidfirst and second mentioned levers for motion transmission and means forchanging the pivot point of said motion transmitting means and therebytheir points of contact with said cam follower levers and said first andsecond mentioned levers.

2. An adapter as claimed in claim 1 wherein said motion transmittingmeans includes a pair of adjustably mounted transmitter levers havinglateral contact pieces slideably contacting said carn follower lever andsaid first and second mentioned levers.

3. An adapter as claimed in claim 2 wherein said second means includes apair of rotary levers pivotally mounted around a common axis and eachpivotally connected to a different one of said transmitter levers, apair of pointers and means connecting each pointer to a different one ofsaid rotary levers for indicating the angular positions of said rotarylevers.

4. An adapter as claimed in claim 1 in which said first lever is anangular lever, said second lever is a straight lever and a common pivotpivotally supports a corner portion of said first lever and an end ofsaid second lever.

5. An adapter as claimed in claim 4 including resilient means tending topivot said first and second levers from one another and furtherresilient means tending to pivot said second lever towards said firstlever.

1. An adapter capable of being detachably mounted on a sewing machinehaving a machine bed and a looper drive shaft driven pinion on said bed,for stitching designs on a work piece comprising a base plate mountableon the sewing machine bed and having an opening for the looper driveshaft driven pinion to extend therethrough, a cam assembly having a rackfor meshing with said pinion and two cam patterns, a work supportingframe, a lever pivotally mounted on said base plate, a link connectingsaid lever to said work frame for imparting lateral movement thereto, asecond lever pivotally mounted on said base plate, a second linkconnecting said second lever to said first link for impartinglongitudinal movement to said work frame, cam followers levers pivotallymounted on said bed plate and each in contact with a different one ofsaid cam patterns, motion transmitting means pivotally supported on saidbase plate and interposed between said cam followers levers and saidfirst and second mentioned levers for motion transmission and means forchanging the pivot point of said motion transmitting means and therebytheir points of contact with said cam follower levers and said first andsecond mentioned levers.
 2. An adapter as claimed in claim 1 whereinsaid motion transmitting means includes a pair of adjustably mountedtransmitter levers having lateral contact pieces slideably contactingsaid cam follower lever and said first and second mentioned levers. 3.An adapter as claimed in claim 2 wherein said second means includes apair of rotary levers pivotally mounted around a common axis and eachpivotally connected to a different one of said transmitter levers, apair of pointers and means connecting each pointer to a different one ofsaid rotary levers for indicating the angular positions of said rotarylevers.
 4. An adapter as claimed in claim 1 in which said first lever isan angular lever, said second lever is a straight lever and a commonpivot pivotally supports a corner portion of said first lever and an endof said second lever.
 5. An adapter as claimed in claim 4 includingresilient means tending to pivot said first and second levers from oneanother and further resilient means tending to pivot said second levertowards said first lever.